From aeed682421a5ebfbf46940e30c3d1caf3bc64304 Mon Sep 17 00:00:00 2001 From: Li Zefan Date: Tue, 29 Jul 2008 22:33:24 -0700 Subject: [PATCH] cpuset: clean up cpuset hierarchy traversal code Use cpuset.stack_list rather than kfifo, so we avoid memory allocation for kfifo. Signed-off-by: Li Zefan Signed-off-by: Lai Jiangshan Cc: Paul Menage Cc: Cedric Le Goater Cc: Balbir Singh Cc: KAMEZAWA Hiroyuki Cc: Paul Jackson Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/cpuset.c | 21 ++++++++------------- 1 file changed, 8 insertions(+), 13 deletions(-) diff --git a/kernel/cpuset.c b/kernel/cpuset.c index 7a82e9033a7f..d5ab79cf516d 100644 --- a/kernel/cpuset.c +++ b/kernel/cpuset.c @@ -54,7 +54,6 @@ #include #include #include -#include #include #include @@ -557,7 +556,7 @@ update_domain_attr_tree(struct sched_domain_attr *dattr, struct cpuset *c) * So the reverse nesting would risk an ABBA deadlock. * * The three key local variables below are: - * q - a kfifo queue of cpuset pointers, used to implement a + * q - a linked-list queue of cpuset pointers, used to implement a * top-down scan of all cpusets. This scan loads a pointer * to each cpuset marked is_sched_load_balance into the * array 'csa'. For our purposes, rebuilding the schedulers @@ -592,7 +591,7 @@ update_domain_attr_tree(struct sched_domain_attr *dattr, struct cpuset *c) void rebuild_sched_domains(void) { - struct kfifo *q; /* queue of cpusets to be scanned */ + LIST_HEAD(q); /* queue of cpusets to be scanned*/ struct cpuset *cp; /* scans q */ struct cpuset **csa; /* array of all cpuset ptrs */ int csn; /* how many cpuset ptrs in csa so far */ @@ -602,7 +601,6 @@ void rebuild_sched_domains(void) int ndoms; /* number of sched domains in result */ int nslot; /* next empty doms[] cpumask_t slot */ - q = NULL; csa = NULL; doms = NULL; dattr = NULL; @@ -622,20 +620,19 @@ void rebuild_sched_domains(void) goto rebuild; } - q = kfifo_alloc(number_of_cpusets * sizeof(cp), GFP_KERNEL, NULL); - if (IS_ERR(q)) - goto done; csa = kmalloc(number_of_cpusets * sizeof(cp), GFP_KERNEL); if (!csa) goto done; csn = 0; - cp = &top_cpuset; - __kfifo_put(q, (void *)&cp, sizeof(cp)); - while (__kfifo_get(q, (void *)&cp, sizeof(cp))) { + list_add(&top_cpuset.stack_list, &q); + while (!list_empty(&q)) { struct cgroup *cont; struct cpuset *child; /* scans child cpusets of cp */ + cp = list_first_entry(&q, struct cpuset, stack_list); + list_del(q.next); + if (cpus_empty(cp->cpus_allowed)) continue; @@ -652,7 +649,7 @@ void rebuild_sched_domains(void) list_for_each_entry(cont, &cp->css.cgroup->children, sibling) { child = cgroup_cs(cont); - __kfifo_put(q, (void *)&child, sizeof(cp)); + list_add_tail(&child->stack_list, &q); } } @@ -735,8 +732,6 @@ rebuild: put_online_cpus(); done: - if (q && !IS_ERR(q)) - kfifo_free(q); kfree(csa); /* Don't kfree(doms) -- partition_sched_domains() does that. */ /* Don't kfree(dattr) -- partition_sched_domains() does that. */ -- 2.20.1